AB1099 SUSTAINED EFFICACY OF BIMEKIZUMAB TREATMENT ASSESSED USING COMPOSITE DISEASE ACTIVITY MEASURES IN PATIENTS WITH PSORIATIC ARTHRITIS AND PRIOR INADEQUATE RESPONSE OR INTOLERANCE TO TUMOUR NECROSIS FACTOR INHIBITORS: RESULTS FROM THE PHASE 3 BE COMPLETE STUDY AND ITS OPEN LABEL EXTENSION UP TO 1 YEAR
Authors: L. Coates, R. B. M. Landewé, I. Mcinnes, C. T. Ritchlin, A. B. Gottlieb, A. M. Orbai, R. B. Warren, B. Ink, R. Bajracharya, J. Coarse, J. F. Merola
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Psoriatic arthritis (PsA) is a disease characterised by heterogeneous joint and skin manifestations, so comprehensive treatment efficacy is best captured by assessment of a broad spectrum of affected domains using composite outcome measures.<sup>[1]</sup> Bimekizumab (BKZ), a monoclonal IgG1 antibody that selectively inhibits interleukin (IL)-17F in addition to IL-17A, has demonstrated superior efficacy and tolerability to 16 weeks (wks) vs placebo (PBO) in patients (pts) with active PsA in the phase 3 BE OPTIMAL and BE COMPLETE studies.<sup>[2,3]</sup> <h3>Objectives</h3> To assess the long-term efficacy of BKZ treatment on disease activity using composite outcome measures in pts with active PsA and prior inadequate response or intolerance to tumour necrosis factor alpha inhibitors (TNFi-IR). <h3>Methods</h3> BE COMPLETE (NCT03896581) comprised a 16-wk double-blind, PBO-controlled period. Pts with PsA and TNFi-IR were randomised 2:1 to subcutaneous BKZ 160 mg every 4 wks or PBO. Pts who completed Wk 16 were eligible for entry into BE VITAL (NCT04009499), an open-label extension (OLE) study. Pts receiving PBO switched to BKZ at Wk 16 (PBO/BKZ). The BE VITAL OLE included pts from BE OPTIMAL and BE COMPLETE. Here, we report data up to 1 year for pts randomised at baseline (Wk 0) of BE COMPLETE (52 wks of study drug). Composite measure data up to Wk 52 are reported: minimal and very low disease activity (MDA/VLDA), the composite endpoint of ≥50% improvement in American College of Rheumatology criteria and 100% improvement in Psoriasis Area and Severity Index response (ACR50+PASI100) in pts with baseline psoriasis (≥3% body surface area [BSA]), Disease Activity Index for Psoriatic Arthritis (DAPSA), and Psoriatic Arthritis Disease Activity Score (PASDAS; collected up to Wk 40). Missing data were imputed using non-responder imputation (NRI) or worst-category imputation. <h3>Results</h3> 388/400 (97.0%) pts completed Wk 16 of BE COMPLETE; 377 (94.3%) entered BE VITAL and 347 (86.8%) completed Wk 52. At Wk 16, a higher proportion of BKZ-treated pts achieved composite disease activity thresholds vs PBO-treated pts. Across all composite outcome measures, efficacy was sustained to Wk 52 in pts randomised to BKZ treatment at Wk 0, and pts who switched to BKZ at Wk 16 demonstrated improvements in efficacy responses to Wk 52 (<b>Figure 1</b>, <b>Table 1</b>). At Wk 16, 6.0% PBO and 44.2% BKZ pts achieved MDA; at Wk 52, this proportion was sustained on BKZ treatment: 33.1% PBO/BKZ and 47.2% BKZ (NRI; <b>Figure 1</b>). Improved or sustained responses were also observed for the proportions of PBO/BKZ and BKZ pts achieving VLDA, ACR50+PASI100, DAPSA and PASDAS thresholds at Wk 52 (<b>Figure 1</b>; <b>Table 1</b>). <h3>Conclusion</h3> BKZ-treated pts with PsA and TNFi-IR demonstrated clinically meaningful improvements in composite measures of disease activity, comprising joint and skin domains, vs PBO at Wk 16. These improvements were sustained up to 1 year on BKZ. Pts who switched to BKZ at Wk 16 showed improvements in efficacy responses up to 1 year. <h3>Reference</h3> [1] Coates LC. Rheum Dis Clin North Am 2015;41(4):699–710; <b>2.</b> McInnes IB. Lancet 2022; DOI: 10.1016/S0140-6736(22)02302-9. <b>3.</b> Merola JF. Lancet 2022; DOI: 10.1016/S0140-6736(22)02303-0. <h3>Acknowledgements</h3> This study was funded by UCB Pharma. Medical writing support was provided by Costello Medical, funded by UCB Pharma. <h3>Disclosure of Interests</h3> Laura Coates Speakers bureau: AbbVie, Amgen, Biogen, Celgene, Eli Lilly, Galapagos, Gilead, GSK, Janssen, medac, Novartis, Pfizer and UCB Pharma, Consultant of: AbbVie, Amgen, BMS, Boehringer Ingelheim, Celgene, Domain, Eli Lilly, Gilead, Galapagos, Janssen, MoonLake, Novartis, Pfizer and UCB Pharma, Grant/research support from: AbbVie, Amgen, Celgene, Eli Lilly, Gilead, Janssen, Novartis, Pfizer and UCB Pharma, Robert B.M. Landewé Consultant of: AbbVie, AstraZeneca, BMS, Eli Lilly, Novartis, Pfizer and UCB Pharma, Grant/research support from: AbbVie, Pfizer, Novartis and UCB Pharma, Employee of: Owner of Rheumatology Consultancy BV, an AMS company under Dutch law, Iain McInnes Consultant of: AbbVie, AstraZeneca, BMS, Boehringer Ingelheim, Cabaletta, Causeway Therapeutics, Celgene, Eli Lilly, Evelo, Janssen, MoonLake, Novartis and UCB Pharma, Grant/research support from: BMS, Boehringer Ingelheim, Celgene, Janssen, Novartis and UCB Pharma, Christopher T. Ritchlin Consultant of: Amgen, AbbVie, Eli Lilly, Gilead, Janssen, Novartis, Pfizer and UCB Pharma, Grant/research support from: AbbVie, Alice B Gottlieb Consultant of: Honoraria as an advisory board member, non-promotional speaker or consultant for Amgen, AnaptysBio, Avotres Therapeutics, BMS, Boehringer Ingelheim, Dermavant, DiCE Therapeutics, Eli Lilly, Janssen, Novartis, Pfizer, Sanofi, Sun Pharma, UCB Pharma and XBiotech (stock options for an RA project), Grant/research support from: AnaptysBio, BMS, Janssen, Novartis, Ortho Dermatologics, Sun Pharma and UCB Pharma; all funds go to the Icahn School of Medicine at Mount Sinai, Ana-Maria Orbai Consultant of: BMS, Janssen, Sanofi and UCB Pharma, Grant/research support from: Research grants to Johns Hopkins University from AbbVie, Amgen and Janssen, Richard B. Warren Consultant of: AbbVie, Almirall, Amgen, Arena, Astellas, Avillion, Biogen, BMS, Boehringer Ingelheim, Celgene, Eli Lilly, GSK, Janssen, LEO Pharma, Novartis, Pfizer, Sanofi and UCB Pharma. Honoraria from Astellas, DiCE, GSK and Union, Grant/research support from: Research grants to his institution from AbbVie, Almirall, Janssen, LEO Pharma, Novartis and UCB Pharma. RBW is supported by the NIHR Manchester Biomedical Centre., Barbara Ink Shareholder of: AbbVie, GSK and UCB Pharma, Employee of: UCB Pharma, Rajan Bajracharya Shareholder of: UCB Pharma, Employee of: UCB Pharma, Jason Coarse Shareholder of: UCB Pharma, Employee of: UCB Pharma, Joseph F. Merola Consultant of: AbbVie, Amgen, Biogen, BMS, Dermavant, Eli Lilly, Janssen, LEO Pharma, Pfizer, Novartis, Regeneron, Sanofi, Sun Pharma and UCB Pharma, Grant/research support from: AbbVie, Amgen, Biogen, BMS, Dermavant, Eli Lilly, Janssen, LEO Pharma, Pfizer, Novartis, Regeneron, Sanofi, Sun Pharma and UCB Pharma.